git.maemo.org Git - wpasupplicant/blob - wpa_supplicant/scan.c

   1 /*
   2  * WPA Supplicant - Scanning
   3  * Copyright (c) 2003-2008, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "eloop.h"
  19 #include "config.h"
  20 #include "wpa_supplicant_i.h"
  21 #include "driver_i.h"
  22 #include "mlme.h"
  23 #include "wps_supplicant.h"
  24 #include "ctrl_iface_dbus.h"
  25
  26
  27 static void wpa_supplicant_gen_assoc_event(struct wpa_supplicant *wpa_s)
  28 {
  29         struct wpa_ssid *ssid;
  30         union wpa_event_data data;
  31
  32         ssid = wpa_supplicant_get_ssid(wpa_s);
  33         if (ssid == NULL)
  34                 return;
  35
  36         if (wpa_s->current_ssid == NULL)
  37                 wpa_s->current_ssid = ssid;
  38         wpa_supplicant_initiate_eapol(wpa_s);
  39         wpa_printf(MSG_DEBUG, "Already associated with a configured network - "
  40                    "generating associated event");
  41         os_memset(&data, 0, sizeof(data));
  42         wpa_supplicant_event(wpa_s, EVENT_ASSOC, &data);
  43 }
  44
  45
  46 #ifdef CONFIG_WPS
  47 static int wpas_wps_in_use(struct wpa_config *conf,
  48                            enum wps_request_type *req_type)
  49 {
  50         struct wpa_ssid *ssid;
  51         int wps = 0;
  52
  53         for (ssid = conf->ssid; ssid; ssid = ssid->next) {
  54                 if (!(ssid->key_mgmt & WPA_KEY_MGMT_WPS))
  55                         continue;
  56
  57                 wps = 1;
  58                 *req_type = wpas_wps_get_req_type(ssid);
  59                 if (!ssid->eap.phase1)
  60                         continue;
  61
  62                 if (os_strstr(ssid->eap.phase1, "pbc=1"))
  63                         return 2;
  64         }
  65
  66         return wps;
  67 }
  68 #endif /* CONFIG_WPS */
  69
  70
  71 static int wpa_supplicant_enabled_networks(struct wpa_config *conf)
  72 {
  73         struct wpa_ssid *ssid = conf->ssid;
  74         while (ssid) {
  75                 if (!ssid->disabled)
  76                         return 1;
  77                 ssid = ssid->next;
  78         }
  79         return 0;
  80 }
  81
  82
  83 static void wpa_supplicant_assoc_try(struct wpa_supplicant *wpa_s,
  84                                      struct wpa_ssid *ssid)
  85 {
  86         while (ssid) {
  87                 if (!ssid->disabled)
  88                         break;
  89                 ssid = ssid->next;
  90         }
  91
  92         /* ap_scan=2 mode - try to associate with each SSID. */
  93         if (ssid == NULL) {
  94                 wpa_printf(MSG_DEBUG, "wpa_supplicant_scan: Reached "
  95                            "end of scan list - go back to beginning");
  96                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
  97                 wpa_supplicant_req_scan(wpa_s, 0, 0);
  98                 return;
  99         }
 100         if (ssid->next) {
 101                 /* Continue from the next SSID on the next attempt. */
 102                 wpa_s->prev_scan_ssid = ssid;
 103         } else {
 104                 /* Start from the beginning of the SSID list. */
 105                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 106         }
 107         wpa_supplicant_associate(wpa_s, NULL, ssid);
 108 }
 109
 110
 111 static int int_array_len(const int *a)
 112 {
 113         int i;
 114         for (i = 0; a && a[i]; i++)
 115                 ;
 116         return i;
 117 }
 118
 119
 120 static void int_array_concat(int **res, const int *a)
 121 {
 122         int reslen, alen, i;
 123         int *n;
 124
 125         reslen = int_array_len(*res);
 126         alen = int_array_len(a);
 127
 128         n = os_realloc(*res, (reslen + alen + 1) * sizeof(int));
 129         if (n == NULL) {
 130                 os_free(*res);
 131                 *res = NULL;
 132         }
 133         for (i = 0; i <= alen; i++)
 134                 n[reslen + i] = a[i];
 135         *res = n;
 136 }
 137
 138
 139 static int freq_cmp(const void *a, const void *b)
 140 {
 141         int _a = *(int *) a;
 142         int _b = *(int *) b;
 143
 144         if (_a == 0)
 145                 return 1;
 146         if (_b == 0)
 147                 return -1;
 148         return _a - _b;
 149 }
 150
 151
 152 static void int_array_sort_unique(int *a)
 153 {
 154         int alen;
 155         int i, j;
 156
 157         if (a == NULL)
 158                 return;
 159
 160         alen = int_array_len(a);
 161         qsort(a, alen, sizeof(int), freq_cmp);
 162
 163         i = 0;
 164         j = 1;
 165         while (a[i] && a[j]) {
 166                 if (a[i] == a[j]) {
 167                         j++;
 168                         continue;
 169                 }
 170                 a[++i] = a[j++];
 171         }
 172         if (a[i])
 173                 i++;
 174         a[i] = 0;
 175 }
 176
 177
 178 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 179 {
 180         struct wpa_supplicant *wpa_s = eloop_ctx;
 181         struct wpa_ssid *ssid;
 182         int scan_req = 0, ret;
 183         struct wpabuf *wps_ie = NULL;
 184         int wps = 0;
 185 #ifdef CONFIG_WPS
 186         enum wps_request_type req_type = WPS_REQ_ENROLLEE_INFO;
 187 #endif /* CONFIG_WPS */
 188         struct wpa_driver_scan_params params;
 189         size_t max_ssids;
 190
 191         if (wpa_s->disconnected && !wpa_s->scan_req)
 192                 return;
 193
 194         if (!wpa_supplicant_enabled_networks(wpa_s->conf) &&
 195             !wpa_s->scan_req) {
 196                 wpa_printf(MSG_DEBUG, "No enabled networks - do not scan");
 197                 wpa_supplicant_set_state(wpa_s, WPA_INACTIVE);
 198                 return;
 199         }
 200
 201         if (wpa_s->conf->ap_scan != 0 &&
 202             (wpa_s->drv_flags & WPA_DRIVER_FLAGS_WIRED)) {
 203                 wpa_printf(MSG_DEBUG, "Using wired authentication - "
 204                            "overriding ap_scan configuration");
 205                 wpa_s->conf->ap_scan = 0;
 206         }
 207
 208         if (wpa_s->conf->ap_scan == 0) {
 209                 wpa_supplicant_gen_assoc_event(wpa_s);
 210                 return;
 211         }
 212
 213         if ((wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) ||
 214             wpa_s->conf->ap_scan == 2)
 215                 max_ssids = 1;
 216         else {
 217                 max_ssids = wpa_s->max_scan_ssids;
 218                 if (max_ssids > WPAS_MAX_SCAN_SSIDS)
 219                         max_ssids = WPAS_MAX_SCAN_SSIDS;
 220         }
 221
 222 #ifdef CONFIG_WPS
 223         wps = wpas_wps_in_use(wpa_s->conf, &req_type);
 224 #endif /* CONFIG_WPS */
 225
 226         if (wpa_s->scan_res_tried == 0 && wpa_s->conf->ap_scan == 1 &&
 227             !(wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) &&
 228             wps != 2) {
 229                 wpa_s->scan_res_tried++;
 230                 wpa_printf(MSG_DEBUG, "Trying to get current scan results "
 231                            "first without requesting a new scan to speed up "
 232                            "initial association");
 233                 wpa_supplicant_event(wpa_s, EVENT_SCAN_RESULTS, NULL);
 234                 return;
 235         }
 236
 237         scan_req = wpa_s->scan_req;
 238         wpa_s->scan_req = 0;
 239
 240         os_memset(&params, 0, sizeof(params));
 241
 242         if (wpa_s->wpa_state == WPA_DISCONNECTED ||
 243             wpa_s->wpa_state == WPA_INACTIVE)
 244                 wpa_supplicant_set_state(wpa_s, WPA_SCANNING);
 245
 246         /* Find the starting point from which to continue scanning */
 247         ssid = wpa_s->conf->ssid;
 248         if (wpa_s->prev_scan_ssid != WILDCARD_SSID_SCAN) {
 249                 while (ssid) {
 250                         if (ssid == wpa_s->prev_scan_ssid) {
 251                                 ssid = ssid->next;
 252                                 break;
 253                         }
 254                         ssid = ssid->next;
 255                 }
 256         }
 257
 258         if (scan_req != 2 && wpa_s->conf->ap_scan == 2) {
 259                 wpa_supplicant_assoc_try(wpa_s, ssid);
 260                 return;
 261         } else if (wpa_s->conf->ap_scan == 2) {
 262                 /*
 263                  * User-initiated scan request in ap_scan == 2; scan with
 264                  * wildcard SSID.
 265                  */
 266                 ssid = NULL;
 267         } else {
 268                 struct wpa_ssid *start = ssid;
 269                 int freqs_set = 0;
 270                 if (ssid == NULL && max_ssids > 1)
 271                         ssid = wpa_s->conf->ssid;
 272                 while (ssid) {
 273                         if (!ssid->disabled && ssid->scan_ssid) {
 274                                 wpa_hexdump_ascii(MSG_DEBUG, "Scan SSID",
 275                                                   ssid->ssid, ssid->ssid_len);
 276                                 params.ssids[params.num_ssids].ssid =
 277                                         ssid->ssid;
 278                                 params.ssids[params.num_ssids].ssid_len =
 279                                         ssid->ssid_len;
 280                                 params.num_ssids++;
 281                                 if (params.num_ssids + 1 >= max_ssids)
 282                                         break;
 283                         }
 284                         ssid = ssid->next;
 285                         if (ssid == start)
 286                                 break;
 287                         if (ssid == NULL && max_ssids > 1 &&
 288                             start != wpa_s->conf->ssid)
 289                                 ssid = wpa_s->conf->ssid;
 290                 }
 291
 292                 for (ssid = wpa_s->conf->ssid; ssid; ssid = ssid->next) {
 293                         if (ssid->disabled)
 294                                 continue;
 295                         if ((params.freqs || !freqs_set) && ssid->scan_freq) {
 296                                 int_array_concat(&params.freqs,
 297                                                  ssid->scan_freq);
 298                         } else {
 299                                 os_free(params.freqs);
 300                                 params.freqs = NULL;
 301                         }
 302                         freqs_set = 1;
 303                 }
 304                 int_array_sort_unique(params.freqs);
 305         }
 306
 307         if (ssid) {
 308                 wpa_s->prev_scan_ssid = ssid;
 309                 if (max_ssids > 1) {
 310                         wpa_printf(MSG_DEBUG, "Include wildcard SSID in the "
 311                                    "scan request");
 312                         params.num_ssids++;
 313                 }
 314                 wpa_printf(MSG_DEBUG, "Starting AP scan for specific SSID(s)");
 315         } else {
 316                 wpa_s->prev_scan_ssid = WILDCARD_SSID_SCAN;
 317                 params.num_ssids++;
 318                 wpa_printf(MSG_DEBUG, "Starting AP scan for wildcard SSID");
 319         }
 320
 321 #ifdef CONFIG_WPS
 322         if (wps) {
 323                 wps_ie = wps_build_probe_req_ie(wps == 2, &wpa_s->wps->dev,
 324                                                 wpa_s->wps->uuid, req_type);
 325                 if (wps_ie) {
 326                         params.extra_ies = wpabuf_head(wps_ie);
 327                         params.extra_ies_len = wpabuf_len(wps_ie);
 328                 }
 329         }
 330 #endif /* CONFIG_WPS */
 331
 332         wpa_supplicant_notify_scanning(wpa_s, 1);
 333
 334         if (wpa_s->drv_flags & WPA_DRIVER_FLAGS_USER_SPACE_MLME) {
 335                 ieee80211_sta_set_probe_req_ie(wpa_s, params.extra_ies,
 336                                                params.extra_ies_len);
 337                 ret = ieee80211_sta_req_scan(wpa_s, params.ssids[0].ssid,
 338                                              params.ssids[0].ssid_len);
 339         } else {
 340                 wpa_drv_set_probe_req_ie(wpa_s, params.extra_ies,
 341                                          params.extra_ies_len);
 342                 ret = wpa_drv_scan(wpa_s, &params);
 343         }
 344
 345         wpabuf_free(wps_ie);
 346         os_free(params.freqs);
 347
 348         if (ret) {
 349                 wpa_printf(MSG_WARNING, "Failed to initiate AP scan.");
 350                 wpa_supplicant_notify_scanning(wpa_s, 0);
 351                 wpa_supplicant_req_scan(wpa_s, 10, 0);
 352         } else
 353                 wpa_s->scan_runs++;
 354 }
 355
 356
 357 /**
 358  * wpa_supplicant_req_scan - Schedule a scan for neighboring access points
 359  * @wpa_s: Pointer to wpa_supplicant data
 360  * @sec: Number of seconds after which to scan
 361  * @usec: Number of microseconds after which to scan
 362  *
 363  * This function is used to schedule a scan for neighboring access points after
 364  * the specified time.
 365  */
 366 void wpa_supplicant_req_scan(struct wpa_supplicant *wpa_s, int sec, int usec)
 367 {
 368         /* If there's at least one network that should be specifically scanned
 369          * then don't cancel the scan and reschedule.  Some drivers do
 370          * background scanning which generates frequent scan results, and that
 371          * causes the specific SSID scan to get continually pushed back and
 372          * never happen, which causes hidden APs to never get probe-scanned.
 373          */
 374         if (eloop_is_timeout_registered(wpa_supplicant_scan, wpa_s, NULL) &&
 375             wpa_s->conf->ap_scan == 1) {
 376                 struct wpa_ssid *ssid = wpa_s->conf->ssid;
 377
 378                 while (ssid) {
 379                         if (!ssid->disabled && ssid->scan_ssid)
 380                                 break;
 381                         ssid = ssid->next;
 382                 }
 383                 if (ssid) {
 384                         wpa_msg(wpa_s, MSG_DEBUG, "Not rescheduling scan to "
 385                                 "ensure that specific SSID scans occur");
 386                         return;
 387                 }
 388         }
 389
 390         wpa_msg(wpa_s, MSG_DEBUG, "Setting scan request: %d sec %d usec",
 391                 sec, usec);
 392         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 393         eloop_register_timeout(sec, usec, wpa_supplicant_scan, wpa_s, NULL);
 394 }
 395
 396
 397 /**
 398  * wpa_supplicant_cancel_scan - Cancel a scheduled scan request
 399  * @wpa_s: Pointer to wpa_supplicant data
 400  *
 401  * This function is used to cancel a scan request scheduled with
 402  * wpa_supplicant_req_scan().
 403  */
 404 void wpa_supplicant_cancel_scan(struct wpa_supplicant *wpa_s)
 405 {
 406         wpa_msg(wpa_s, MSG_DEBUG, "Cancelling scan request");
 407         eloop_cancel_timeout(wpa_supplicant_scan, wpa_s, NULL);
 408 }
 409
 410
 411 void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 412                                     int scanning)
 413 {
 414         if (wpa_s->scanning != scanning) {
 415                 wpa_s->scanning = scanning;
 416                 wpa_supplicant_dbus_notify_scanning(wpa_s);
 417         }
 418 }
 419